Dry-plate-developing device.



No. 775,001; PATENTBD NOV. 15, 1904.

W. BULLOCK.

DRY PLATE DEVELOPING DEVICE.

APPLICATION FILED FEB. 25. 1903.

N0 MODEL.

WITNESSES: lNVENTOH,

' I WILLmMEIuLLucK,

A TTOHNE )1 UNTTED STATES Patented November 15, 1904.

WILLIAM BULLOCK, OF CLEVELAND, OHIO.

DRY-PLATE-DEVELOPING DEVICE.

SPECIFICATION forming part of Letters Patent No. 775,001, dated November 15, 1904.

Application filed February 25,1903. Serial No. 144,930- (No model.)

T0 to whom, it may concern.-

Be it known that I,WILLIAM BULLOCK, a citi- Zen of the United States of America, and a resident of Cleveland, in-the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Dry-Plate-Developing Devices, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to improvements in dry-plate-developing devices, and has for its object the provision of simple, portable, and entirely convenient apparatus for the development and fixing of photographic'plates irrespective of the light, while avoiding the employment of any cumbersome appliance in substitution for the ordinary dark room.

The results sought to be attained directly by my improvements may be said to be twofold, the one being the immediate development of an experimental or test plate to determine the proper exposure for any given light, while the other looks toward the completion of the negatives for printing purposes without involving the use of a dark room.

Those conversant with photography will appreciate the marked advantages to be secured with apparatus satisfactorily attaining the above results, some of which will later be indicated herein.

Preliminary to a fuller disclosure of apparatus embodying my invention I may say that the same consists of a plate-holder constructed of suitable material, practically impervious and unaffected by liquids, wherein the dry-plate may be insertedand exposed in the usual manner within the camera. Its construction. is such, of course, that the light is excluded from the interior of the plate-holder, while the same is further adapted to permit the entrance of the necessary fluids for completing the negative. One form of such plateholder adapted for the accommodation of but a single plate preferably has a liquid chamber or channel within the space ordinarily occupied by the second dry-plate, by means of which the developing and fixing fluids may be introduced to the contained plate. This is especially adapted for test exposures. An immersing-tank or developing-case constructed to fit the plate-holder, preferably being of such size that a relatively small volume of liquid is required for the immersion of the latter, is also employed with an impervious plate-holder for developing the negative.

Further details of construction and usewill be made clear by referring to the accompanying drawings, wherein Figure l is a plan view of a combined plate holder and developing device adapted to contain a single dry-plate and having a special chamber or channel for the introduction of the developing and fixing fluids, the slide being shown nearly withdrawn from the frame and broken away. Fig. 2 is a central crosssectional view of the same device. Fig. 3 is a bottom view thereof, and Fig. 4 is a side elevation of the developing-case with an impervious plate-holder partially immersed or inserted therein.

Throughout the several figures of the drawings I have employed the same characters of reference to indicate similar parts.

Because of its subjection to the various fluids or liquids in developing and preparing the negative the plate-holder must be constructed of suitable material, such as metal, (zinc or aluminium being desirable,) rubber, fiber, treated wood, or other impervious substance practically unaffected by such fluids. Structurally the plate-holder itself does not difl'er materially from well-known types or models, being adapted to be placed in the ordinary makes of cameras and occupying the same space required by the commonly-used double plate-holder. In my combined plate holder and developer, however, as herein shown, the receptacle or compartment for the second dryplate is displaced or supplanted by a liquid chamber or channel whereby the single contained dry-plate may after exposure be subjected to the action of the developing and iixing fluids without removing said plate or withdrawing the slide.

Assuming the plate-holder tobe lying flat, as shown in the sectional view, the upper half is seen to comprise the plate-holding compartment the frame a being equipped with the usual light-excluding slide 6 to be withdrawn when the device is inserted in the camera for exposure, said slide preferably being loosely fitted within the frame to permit the flow of liquids therebetween for a purpose to be explained. In the divisional partition or diaphragm 0. will be noted openings 0, communicating with the lower portion or liquid'chamber (Z, provided in the device. This chamber or channel preferably is of restricted size and extending half the length of the plate-holder and upon either side thereof terminates in an external opening fitted with a short protruding tube (Z at the end of the frame opposite that from which the slide is withdrawn. This liquid chamber or channel being open to the external light and air is interiorly flowed with a black lacquer or other darkening-pigment and is constructed of rectangular form substantially one-half the length of the frame, the opening (Z being disposed with respect to the channel, so that thelight cannot enter the plate-holding compartment through the displaced diaphragm-openings By constructing this channel of small size a relatively small quantity of liquid only will be required for overflowing the plate.

The developing case or bath a is simply a vertical tank wherein a suitable plate-holder may be immersed and retained in position by means of its light-stop coming into engagement with the rim of the case. An opening a in one side of said case permits the height of the liquid therein to be observed and affords as well an overflow for any excess of the contained fluid. The size of the developing-case preferably is calculated closely to contain or fit about the introduced plateholder, so that practically all of the fluid therein will find entrance to the interior of said plate-holder.

A small funnel f is removably fitted upon the tube (Z by means of a short length of rul ber tubing when the exposed dry-plate is to be developed. In Fig. 1 a kit for holding a plate of smaller dimensions is shown as occupying the place of a normal-sized plate.

The manner of using the apparatus just described will now be readily appreciated. Assuming that the combined plate holder and developer contains an exposed dry-plate,standard developing fluid is poured through the funnel f and channel (Z and rising centrally in the plate-holding compartment overflows the dry-plate, driving the air before it and appearing around the overlapping edges of the frame, the slide of course beingkept closed. The device is then tilted or slightly shaken for a few seconds and a little more of the fluid is poured into the funnel. hen a fourby-five-inch plate is treated, three or four ounces of standard developing fluid will be required, which at Fahrenheit will properly develop the contained plate in three minutes. This flooding of the plate from the center satisfactorily overcomes the tendency to form air-bubbles thereon, which of course would prevent the proper development of the negative. The developing fluid is then drained off and water is poured into the device to wash out the traces of the fluid remaining. Fixing fluid is then poured into the device, as before, which will serve to fix the negative in about live minutes, after which the plate may be removed or left to dry within the holder, as desired. In many instances it will be found more convenient to fix or develop and fix the negatives in the developingcase 0 instead, in which event the proper fluid is poured into said case or tank (six or seven ounces then being required under the conditions assumed) and a suitable impervious plateholder containing the exposures is slowly lowered therein, as indicated in Fig. 4:, the air thus being displaced. Otherwise the directions previously given may be followed. The slides, as explained, should not be so tightly fitted that the fluids cannot filter into the plate-holding portions of the holder, whereby exposed plates may be immediately developed and fixed for printing within the closed lightexcluding plate-holder, or the developing fluid may be poured into the combined plate holder and developer and then washed out with water, as described, after which the device may be immersed in fixing fluid contained in case permitting the use of the latter fluid again and again.

By, employing my improved apparatus it will be seen that a test plate or negative for determining future exposures may easily be made at any time, using several different periods of exposure, if desired, by successive partial withdrawals of the slide, and, furthermore, that other plate-holders made in accordance with my instructions may be treated to develop the negatives for printing without the aid of a dark room, changing-bag, or other substitute therefor. This, I wish to emphasize, is all accomplished solely within the plateholder proper and, in consequence, without the removal of the dry-plates or withdrawal of the slides which, as explained, are so fitted as to permit the flow of air and liquids while at the same time excluding the light. My improved devices accordingly may be used in the ordinary makes of cameras without altering the latter or adding attachments of any kind.

Having now described the principles of my invention and the preferred type of apparatus embodying the same, I claim, together with all proper modifications thereof, the following:

1. The combination in dry-plate holding and developing apparatus, with an impervious plate-holder, of its light-excluding slide loosely fitted therein to permit the entrance and exit of the developing and fixing fluids, and a closely-fitting developing-case therefor adapted to receive the same and subject its contents to practically all the fluid contained in said developing-case. substantially as set forth.

2. In a combined plate holder and developer,

the combination With the plate-holding compartment, having a liquid-channel of restricted size communicating With said compartment and with the external air, and means for excluding the light from the communicating openings and for supplying fluids to the plate only from its middle portion, substantially as set forth.

3. In acombined plate holder and developer, the combination With a plate-holding compartment disposed in the upper portion thereof, of the light-excluding slide, said compartment having a lower liquid-channel communicating With said compartment only adjacent to its middle portion, and also With the external air, and means for excluding the. light from ing Witnesses.

- WILLIAM BULLOCK. Witnesses:

IsAAo O. TrrUs, ALBERT LYNN LAURENCE. 

